1. Field of the Invention
The present disclosure pertains to defrosting a component of an oxygen liquefier, and, in particular, defrosting an oxygen line in an oxygen concentrator and liquefier system to remove a whole or partial blockage caused by frozen liquid, such as water, within the oxygen line.
2. Description of the Related Art
It is well known to liquefy oxygen and other gases. Many gases can be put into a liquid state at normal atmospheric pressure by simple cooling; a few, such as carbon dioxide, require pressurization as well. Some gas liquefiers typically rely on the absence of moisture in the gas to be liquefied. Some of the standard techniques used to remove moisture include the use of membranes, adsorption, absorption, and/or cryogenic distillation.
However, oxygen coming directly from a standard pressure swing adsorption (PSA) system used as an oxygen concentrator may still contain trace amounts of moisture. In some instances, for example, the trace amounts of moisture may have a dew point of approximately −60° C. As a result, ice may form within gas lines during liquefaction of oxygen coming from a PSA system, thus restricting or blocking oxygen flow and/or acting as an insulator reducing heat exchange efficiency.